The overall goals ofthe program project grant (PPG) and individual projects require primary human cells from the two human subjects protocols described in Core A (Clinical Core). The goal of Core B (Laboratory Core) is to process the clinical samples from the human subjects protocols to provide high quality cells to each project for planned in vitro experiments and future analysis of clinical samples. Specific Task 1: Isolate purified eosinophils (EOS) and other cell populations from peripheral blood donors. Subjects that have been well characterized by Core A (Clinical Core) for the blood donor protocol will be recruited for peripheral blood donation. Using gradient centrifugation and magnetic bead negative separation techniques, purified EOS and/or other cell types (e.g. monocytes and CD4^ T cells) will be prepared for in vitro experimental use by the PPG projects. Spcicific Task 2: Process bronchoalveolar lavage (BAL) samples to isolate EOS and other cell populations. BAL fluid derived from subjects enrolled in the Core A (Clinical Core) protocol will be collected. Using gradient centrifugation and other cell separation techniques, purified EOS and/or other cell types (e.g. monocytes and T cells) will be prepared for in vitro experimental use by the PPG projects. Specific Task 3: Adapt current protocols to the requirements of each project. Any ofthe protocols in the first two tasks and other EOS functional assays will be adapted for the needs of any project. RELEVANCE (See instructions): The relevance ofthe Laboratory Core is to provide critical and high quality purified EOS from blood and BAL as well as monocytes, 004 T cells, and neutrophils from blood to the three projects to interrogate the role of EOS in airway remodeling associated with asthma.